Apple has a voluntary recall and free battery replacement program for certain 15-inch MacBook Pro models sold between 2015 and 2017.  These units can be identified by serial number at support.apple.com/15-inch-macbook-pro-battery-recall.

This recall is currently one of the programs available at Apple’s Exchange and Repair Extension Program page.

Apple also announced a partnership with Best Buy which designates their stores as Apple authorized repair locations.